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<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <!-- 计算1-1000之间的累加和，并且打印输出到页面中 -->
    <script>
        let num = 0;
        for (i = 1; i <= 1000; i++) {
            num += i

        }
        document.write(num)
    </script>
</body>

</html>